a. 1. Not likely; improbable; not to be reasonably expected; as, an unlikely event; the thing you mention is very unlikely. [ 1913 Webster ]
2. Not holding out a prospect of success; likely to fail; unpromising; as, unlikely means. Hooker. [ 1913 Webster ]
3. Not such as to inspire liking; unattractive; disagreeable. [ Obs. ] “The unlikely eld of me.” Chaucer. [ 1913 Webster ]
adv. In an unlikely manner. [ 1913 Webster ]